Welcome aboard! We used to stay offsite for many many years and we had a really good time. But, we stayed onsite for the first time four years ago and I'll never go back to offsite again. (unless that is the absolute only way I could go to Disney)
If you stay onsite:
1) If you fly, Disney will pick you and your bags up from the airport and take you directly to your resort;
2) If you drive to Florida, you can simply park your car in the resort parking lot and let Disney drive you anywhere on Disney property. Free of charge. No hassling with traffic and no gas expense. If you do decide to drive your car to the theme parks, there is no parking charge.
3) You are entitled to extra hours in the theme parks on certain days. The morning hours are 1 hour prior to official opening for offsite guests and the evening hours are sometimes up to three hours after park closing for offsite guests.
4) You can also purchase the dining plan and have all of your meals paid for before you ever even get to Disney.
If you stay offsite:
1) If you fly in, you'll have to take a car service or taxi to get to your rental home;
2) If you drive your own car and drive to the theme parks, you have to pay a fee to park. I think it's now about $12.00 a day;
3) You don't have extra hours privileges;
4) You'll have to pay out of pocket for all of your meals which can add up very quickly.
When were you thinking of traveling? Have you checked out all of the Disney resorts?